Method for recognizing thief zone in oil pool, computer apparatus and computer readable storage medium

ABSTRACT

A method for recognizing a thief zone in an oil pool, a computer apparatus and a computer readable storage medium, wherein, the method comprises: calculating a yield contribution value per unit thickness for single-reservoir stratum and a relative contribution coefficient of individual reservoir stratum in oil pool production logging, the relative contribution coefficient being a ratio of the yield contribution value per unit thickness for single-reservoir stratum to a yield per unit thickness for the whole reservoir stratum interval; determining a smallest yield contribution value per unit thickness for single-reservoir stratum and a smallest relative contribution coefficient from the yield contribution values per unit thickness for single-reservoir stratum and the relative contribution coefficients in the oil pool production logging, according to the characteristics of different oil pools; calculating the yield contribution value per unit thickness for single-reservoir stratum and the relative contribution coefficient of each reservoir stratum of each well in the oil pool to-be-measured; determining whether or not a thief zone is developed for each reservoir stratum of each well according to a magnitude relationship between the yield contribution value per unit thickness for single-reservoir stratum of each reservoir stratum of each well and the smallest yield contribution value per unit thickness for single-reservoir stratum and according to the magnitude relationship between the relative contribution coefficient of each reservoir stratum of each well and the smallest relative contribution coefficient.

TECHNICAL FIELD

The present invention relates to the technical field of carbonatite oilpool exploitation, in particular to a method for recognizing a thiefzone in an oil pool, a computer apparatus, and a computer readablestorage medium.

BACKGROUND

A thief zone refers to a thin reservoir stratum which has a permeabilitymuch higher than the average permeability of the reservoir stratums,fluids mainly flow along the thief zone, causing the water breakthroughto be too fast, which greatly reduces the swept volume, results ininvalid circulation of water injection and affects the overalldevelopment effect of the oil field. At present, the thief zone isgenerally recognized and represented by means of geological static data,yield, liquid production index, production increase contribution rate,single-layer liquid production index, dimensionless pressurecoefficient, etc. However, these dynamic and static recognition methodsall have certain limitations. The thief zone cannot be recognizedquantitatively based on the geological static data; when the thief zoneis recognized based on yield data, the concept of production pressuredifferential is not taken into consideration; when the thief zone isdivided according to the indexes such as the liquid production index,the production increase contribution rate, the single-layer liquidproduction index and the dimensionless pressure coefficient, thelimitation conditions such as reservoir thickness or extremely poorpermeability are not taken into consideration. Up to now, there is stillnot a method that can recognize the thief zone fast and accurately.

SUMMARY

The embodiments of the present invention provide a method forrecognizing a thief zone in an oil pool in order to solve the technicalproblem that the thief zone recognition has a low accuracy in the priorart. The method comprises: calculating a yield contribution value perunit thickness for single-reservoir stratum and a relative contributioncoefficient of individual reservoir stratum in oil pool productionlogging, wherein, the yield contribution value per unit thickness forsingle-reservoir stratum is a ratio of a single-reservoir stratum yieldto a single-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval; determining a smallest yieldcontribution value per unit thickness for single-reservoir stratum and asmallest relative contribution coefficient from the yield contributionvalues per unit thickness for single-reservoir stratum and the relativecontribution coefficients in the oil pool production logging, accordingto the characteristics of different oil pools, wherein, the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient meet the requirementsof thief zone recognition for different oil pools; calculating the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient of each reservoir stratum of eachwell in the oil pool to-be-measured; determining whether or not a thiefzone is developed for each reservoir stratum of each well according to amagnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.

The embodiments of the present invention also provide a computerapparatus in order to solve the technical problem that the thief zonerecognition has a low accuracy in the prior art. The computer apparatuscomprises: a processor; and a memory comprising computer readableinstructions. The processor is enabled to execute the followingoperations when the computer readable instructions are executed:calculating a yield contribution value per unit thickness forsingle-reservoir stratum and a relative contribution coefficient ofindividual reservoir stratum in oil pool production logging, wherein,the yield contribution value per unit thickness for single-reservoirstratum is a ratio of a single-reservoir stratum yield to asingle-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval; determining a smallest yieldcontribution value per unit thickness for single-reservoir stratum and asmallest relative contribution coefficient from the yield contributionvalues per unit thickness for single-reservoir stratum and the relativecontribution coefficients in the oil pool production logging, accordingto the characteristics of different oil pools, wherein, the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient meet the requirementsof thief zone recognition for different oil pools; calculating the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient of each reservoir stratum of eachwell in the oil pool to-be-measured; determining whether or not a thiefzone is developed for each reservoir stratum of each well according to amagnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.

The embodiments of the present invention also provide a computerreadable storage medium comprising computer readable instructions inorder to solve the technical problem that the thief zone recognition hasa low accuracy in the prior art. The computer readable instructionsenable the processor to at least execute the following operations whenthe computer readable instructions are executed: calculating a yieldcontribution value per unit thickness for single-reservoir stratum and arelative contribution coefficient of individual reservoir stratum in oilpool production logging, wherein, the yield contribution value per unitthickness for single-reservoir stratum is a ratio of a single-reservoirstratum yield to a single-reservoir stratum thickness, and the relativecontribution coefficient is a ratio of the yield contribution value perunit thickness for single-reservoir stratum to a yield per unitthickness for the whole reservoir stratum interval; determining asmallest yield contribution value per unit thickness forsingle-reservoir stratum and a smallest relative contributioncoefficient from the yield contribution values per unit thickness forsingle-reservoir stratum and the relative contribution coefficients inthe oil pool production logging, according to the characteristics ofdifferent oil pools, wherein, the smallest yield contribution value perunit thickness for single-reservoir stratum and the smallest relativecontribution coefficient meet the requirements of thief zone recognitionfor different oil pools; calculating the yield contribution value perunit thickness for single-reservoir stratum and the relativecontribution coefficient of each reservoir stratum of each well in theoil pool to-be-measured; determining whether or not a thief zone isdeveloped for each reservoir stratum of each well according to amagnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.

In the embodiments of the present invention, the yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient of individual reservoir stratum in the oil poolproduction logging are calculated (for example, the yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient of individual reservoir stratum in the oil poolproduction logging can be calculated based on dynamic monitoring data ofthe oil pool production logging), the smallest yield contribution valueper unit thickness for single-reservoir stratum and the smallestrelative contribution coefficient are determined according to thecharacteristics of different oil pools, and at last, whether or not athief zone is developed for each reservoir stratum of each well can bedetermined fast according to a magnitude relationship between the yieldcontribution value per unit thickness for single-reservoir stratum ofeach reservoir stratum of each well and the smallest yield contributionvalue per unit thickness for single-reservoir stratum and according to amagnitude relationship between the relative contribution coefficient ofeach reservoir stratum of each well and the smallest relativecontribution coefficient. Since the calculation of the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient has fully considered the influenceof thickness on yield contribution, the thief zone recognition isallowed to be more in line with actual situations, thus helpingimproving the accuracy of the thief zone recognition.

BRIEF DESCRIPTION OF THE DRAWINGS

To explain the technical solutions in the embodiments of the presentinvention more clearly, the following will briefly introduce the figuresneeded in the description of the embodiments. Obviously, the figures inthe following description are only some embodiments of the presentinvention, and for ordinary skilled persons in the art, other figuresmay also be obtained based on these figures without paying any creativeefforts. In the figures:

FIG. 1 is a flow chart of a method for recognizing a thief zone in anoil pool in the embodiments of the present invention;

FIG. 2 is a discrimination graph of the thief zone recognition in theembodiments of the present invention;

FIG. 3 is a schematic diagram of the thief zone recognition in acarbonatite oil pool in the embodiments of the present invention;

FIG. 4 is a block diagram of the structure of a computer apparatus inthe embodiments of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

In order to make the object, the technical solutions and the advantagesof the present invention more clear, the following will provide afurther detailed description of the embodiments of the present inventionin combination with the figures. Here, the exemplary embodiments of thepresent invention and the description thereof are intended forexplaining the present invention, not for limiting the presentinvention.

FIG. 1 is a flow chart of a method for recognizing a thief zone in anoil pool in the embodiments of the present invention. As shown in FIG.1, the method for recognizing a thief zone in an oil pool in theembodiments of the present invention can comprise:

Step 101: calculating a yield contribution value per unit thickness forsingle-reservoir stratum and a relative contribution coefficient ofindividual reservoir stratum in oil pool production logging, wherein,the yield contribution value per unit thickness for single-reservoirstratum is a ratio of a single-reservoir stratum yield to asingle-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval;

Step 102: determining a smallest yield contribution value per unitthickness for single-reservoir stratum and a smallest relativecontribution coefficient from the yield contribution values per unitthickness for single-reservoir stratum and the relative contributioncoefficients in the oil pool production logging, according to thecharacteristics of different oil pools, wherein, the smallest yieldcontribution value per unit thickness for single-reservoir stratum andthe smallest relative contribution coefficient meet the requirements ofthief zone recognition for different oil pools;

Step 103: calculating the yield contribution value per unit thicknessfor single-reservoir stratum and the relative contribution coefficientof each reservoir stratum of each well in the oil pool to-be-measured;

Step 104: determining whether or not a thief zone is developed for eachreservoir stratum of each well, according to a magnitude relationshipbetween the yield contribution value per unit thickness forsingle-reservoir stratum of each reservoir stratum of each well and thesmallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.

As can be seen from FIG. 1, in the embodiments of the present invention,whether or not a thief zone is developed for each reservoir stratum ofeach well can be determined fast by: calculating the yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient of individual reservoir stratum in the oil poolproduction logging (for example, the yield contribution value per unitthickness for single-reservoir stratum and the relative contributioncoefficient of individual reservoir stratum in the oil pool productionlogging can be calculated based on dynamic monitoring data of the oilpool production logging), and determining the smallest yieldcontribution value per unit thickness for single-reservoir stratum andthe smallest relative contribution coefficient according to thecharacteristics of different oil pools, and at last, whether or not athief zone is developed for each reservoir stratum of each well can bedetermined fast according to a magnitude relationship between the yieldcontribution value per unit thickness for single-reservoir stratum ofeach reservoir stratum of each well and the smallest yield contributionvalue per unit thickness for single-reservoir stratum and according to amagnitude relationship between the relative contribution coefficient ofeach reservoir stratum of each well and the smallest relativecontribution coefficient. Since the calculation of the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient has fully considered the influenceof thickness on yield contribution, the thief zone recognition isallowed to be more in line with actual situations, thus helpingimproving the accuracy of the thief zone recognition.

In a concrete implementation, it is possible to obtain all thesingle-well single-layer (i.e., single-reservoir stratum) thicknessesand the corresponding single-layer yields based on monitoring data onthe production logging on site, and thereby obtain a single-layerthickness percentage and a single-layer yield percentage, and at lastcalculate the yield contribution value per unit thickness forsingle-reservoir stratum and the relative contribution coefficient (RCI)by using the single-well single-layer yield, the single-layer thickness,the single-layer thickness percentage and the single-layer yieldpercentage.

In a concrete implementation, it is assumed that the reservoir stratuminterval has n single layers, the yield of the i^(th) layer is Q_(i),the thickness of the i^(th) layer is h_(i), the total yield of thereservoir stratums is Q_(t), and the total thickness of the reservoirstratums is h_(t). The abscissa in the thief zone recognition graph(i.e., the yield contribution value per unit thickness forsingle-reservoir stratum) is a ratio of the single-layer yield to thesingle-layer thickness, i.e., the yield contribution value per unitthickness for single-reservoir stratum, this parameter can effectivelysolve the problem that the thickness of the thief zone is not consideredin the previous methods for recognizing a thief zone.

In a concrete implementation, in order to recognize the thief zone morequickly, in this embodiment, the step of determining whether or not athief zone is developed for each reservoir stratum of each wellaccording to a magnitude relationship between the yield contributionvalue per unit thickness for single-reservoir stratum of each reservoirstratum of each well and the smallest yield contribution value per unitthickness for single-reservoir stratum and according to a magnituderelationship between the relative contribution coefficient of eachreservoir stratum of each well and the smallest relative contributioncoefficient comprises: drawing a graph by taking the yield contributionvalue per unit thickness for single-reservoir stratum of individualreservoir stratum in the oil pool production logging as an ordinate andthe relative contribution coefficient of individual reservoir stratum inthe oil pool production logging as an abscissa, wherein, an intersectionline of the smallest yield contribution value per unit thickness forsingle-reservoir stratum and the smallest relative contributioncoefficient divides the graph into different areas; and determiningwhether or not a thief zone is developed for each reservoir stratum ofeach well according to the distribution positions of the yieldcontribution value per unit thickness for single-reservoir stratum ofeach reservoir stratum of each well and the relative contributioncoefficient of each reservoir stratum of each well in different areas ofthe graph.

To be specific, as shown in FIG. 2, after the graph has been drawn withthe yield contribution value per unit thickness for single-reservoirstratum of individual reservoir stratum in the oil pool productionlogging as the ordinate and the relative contribution coefficient ofindividual reservoir stratum in the oil pool production logging as theabscissa, the intersection line of the smallest yield contribution valueper unit thickness for single-reservoir stratum and the smallestrelative contribution coefficient divides the graph into differentareas, i.e., the intersection line of the smallest yield contributionvalue per unit thickness for single-reservoir stratum and the smallestrelative contribution coefficient divides the graph into different areasaccording to the magnitude relationships of the coordinate values withthe smallest yield contribution value per unit thickness forsingle-reservoir stratum and the smallest relative contributioncoefficient. The areas are, for example, a thief zone-developed area, athief zone-undeveloped area and an area that is not considered due toexcessively low yield per unit thickness. Whether or not a thief zone isdeveloped can be determined quickly according to the distributionpositions of the data of each reservoir stratum of each well in thedifferent areas.

In a concrete implementation, the step of determining whether or not athief zone is developed for each reservoir stratum of each wellaccording to a magnitude relationship between the yield contributionvalue per unit thickness for single-reservoir stratum of each reservoirstratum of each well and the smallest yield contribution value per unitthickness for single-reservoir stratum and according to a magnituderelationship between the relative contribution coefficient of eachreservoir stratum of each well and the smallest relative contributioncoefficient comprises: not judging the reservoir stratum of which theyield contribution value per unit thickness for single-reservoir stratumis smaller than the smallest yield contribution value per unit thicknessfor single-reservoir stratum; determining the reservoir stratum of whichthe yield contribution value per unit thickness for single-reservoirstratum is greater than the smallest yield contribution value per unitthickness for single-reservoir stratum and the relative contributioncoefficient is smaller than the smallest relative contributioncoefficient to be a non-thief zone; and determining the reservoirstratum of which the yield contribution value per unit thickness forsingle-reservoir stratum is greater than the smallest yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient is greater than the smallest relativecontribution coefficient to be a thief zone.

In a concrete implementation, the smallest yield contribution value perunit thickness for single-reservoir stratum and the smallest relativecontribution coefficient can be determined with respect to different oilpools. The single layer of which the yield contribution value per unitthickness for single-reservoir stratum is too low is not sufficient toinfluence the water-flooding development of the oil pool, and does nothave a value for thief zone recognition. Thus, there is a need ofdetermining the smallest yield contribution value per unit thickness forsingle-reservoir stratum. Due to the differences in the factors such asthe physical properties of the oil pool, the smallest yield contributionvalues per unit thickness for single-reservoir stratum of different oilpools should be different, and generally can be a half of the averagevalue of the yield contribution values per unit thickness forsingle-reservoir stratum. For example, for a carbonatite oil pool, thesmallest yield contribution value per unit thickness forsingle-reservoir stratum can be 50 stb/ft. The higher the smallestrelative contribution coefficient is, the greater the productivity ofthe single layer is. The contribution of the productivity of the thiefzone is greater than that of the overall productivity of the reservoirstratums. In general, the relative contribution coefficient for thiefzone judging is defined to a value greater than or equal to 2. Forexample, for a carbonatite oil pool, the smallest relative contributioncoefficient is 2.

The following will give a description of the above method forrecognizing a thief zone in an oil pool in combination with concreteexamples. The carbonatite oil pool is taken as an example.

(1) Data Collection and Data Quality Control

The method is used to recognize the position of the thief zone, thecollected data is the production logging data of the carbonatite oilpool, specifically including all the single-layer thicknesses and thecorresponding single-layer yields. The recognition process can beinitiated after all the data has been collected and the quality controlthereof has been conducted.

This embodiment is based on the result of preliminary screening, thedata of 110 single layers of 25 wells is obtained, and the yieldcontribution values per unit thickness for single-reservoir stratum andrelative contribution coefficients (RCI) are calculated using thesingle-layer yield, the single-layer thickness, the single-layerthickness percentage and the single-layer yield percentage. The resultis shown in Table 1.

TABLE 1 Data of a group of candidate wells for carbonatite thief zonerecognition Single-layer Single-layer Single-layer yield contributionrelative Well Single-layer thickness Single-layer yield value per unitcontribution number thickness (m) percentage (%) yield (stb) percentage(%) thickness (stb/m) coefficient W1 4.00 15.38 328.00 18.93 82.00 1.23W1 7.00 26.92 35.60 2.05 5.09 0.08 W1 4.00 15.38 98.90 5.71 24.73 0.37W1 4.00 15.38 440.00 25.40 110.00 1.65 W1 7.00 26.92 830.00 47.91 118.571.78 W2 6.00 27.27 175.00 12.08 29.17 0.44 W2 4.00 18.18 152.00 10.4938.00 0.58 W2 4.00 18.18 19.00 1.31 4.75 0.07 W2 3.00 13.64 362.00 24.98120.67 1.83 W2 5.00 22.73 741.00 51.14 148.20 2.25 W3 1.00 4.55 206.0019.32 206.00 4.25 W3 2.00 9.09 450.00 42.21 225.00 4.64 W3 5.00 22.7351.00 4.79 10.20 0.21 W3 4.00 18.18 116.00 10.88 29.00 0.60 W3 4.0018.18 0.00 0.00 0.00 0.00 W3 3.00 13.64 142.00 13.32 47.33 0.98 W3 3.0013.64 101.00 9.48 33.67 0.70 W4 4.27 26.42 68.30 10.20 16.00 0.39 W43.96 24.50 68.00 10.10 17.17 0.41 W4 3.35 20.73 200.00 29.80 59.70 1.44W4 3.05 18.87 0.00 0.00 0.00 0.00 W4 1.53 9.47 334.00 49.80 218.30 5.26W5 11.00 36.67 0.00 0.00 0.00 0.00 W5 5.00 16.67 0.00 0.00 0.00 0.00 W56.00 20.00 410.00 32.80 68.33 1.64 W5 8.00 26.67 840.00 67.20 105.002.52 W6 4.50 13.04 5.00 0.60 1.11 0.05 W6 30.00 86.96 835.00 99.64 27.831.15 W7 2.50 27.78 480.00 30.38 192.00 1.09 W7 1.50 16.67 640.00 40.51426.67 2.43 W7 5.00 55.56 460.00 29.11 92.00 0.52 W8 21.00 57.53 1016.0034.75 48.38 0.60 W8 5.50 15.07 46.00 1.57 8.36 0.10 W8 10.00 27.401862.00 63.68 186.20 2.32 W9 6.25 17.11 242.00 5.70 38.72 0.33 W9 8.0822.12 994.00 23.30 123.02 1.05 W9 3.81 10.43 258.00 6.00 67.72 0.58 W92.89 7.91 0.00 0.00 0.00 0.00 W9 1.83 5.01 0.00 0.00 0.00 0.00 W9 3.6610.02 0.00 0.00 0.00 0.00 W9 3.50 9.58 1089.00 25.50 311.14 2.66 W9 3.8110.43 62.90 1.50 16.51 0.14 W9 2.69 7.37 1625.00 38.00 604.09 5.16 W103.20 31.16 283.28 10.09 88.52 0.32 W10 2.09 20.35 838.62 29.88 401.251.47 W10 4.98 48.49 1684.50 60.02 338.25 1.24 W11 9.00 14.52 1300.0034.99 144.44 2.41 W11 23.00 37.10 1450.00 39.03 63.04 1.05 W11 30.0048.39 965.00 25.98 32.17 0.54 W12 8.08 11.86 714.00 15.40 88.37 1.30 W123.50 5.14 0.00 0.00 0.00 0.00 W12 7.77 11.41 459.00 9.90 59.07 0.87 W1217.07 25.06 1998.00 43.00 117.05 1.72 W12 26.06 38.26 1214.00 26.1046.58 0.68 W12 5.64 8.28 265.00 5.70 46.99 0.69 W13 10.00 36.63 913.0023.99 91.30 0.66 W13 8.10 29.67 2316.00 60.87 285.93 2.05 W13 5.10 18.68289.00 7.60 56.67 0.41 W13 4.10 15.02 185.00 4.86 45.12 0.32 W14 8.0022.22 660.00 13.27 82.50 0.60 W14 21.00 58.33 3180.00 63.92 151.43 1.10W14 7.00 19.44 1135.00 22.81 162.14 1.17 W15 2.00 16.95 60.08 7.08 30.040.42 W15 2.80 23.73 230.37 27.15 82.27 1.14 W15 3.00 25.42 50.72 5.9816.91 0.24 W15 4.00 33.90 507.40 59.79 126.85 1.76 W16 2.50 21.74 934.0061.21 373.60 2.82 W16 6.00 52.17 592.00 38.79 98.67 0.74 W16 3.00 26.090.00 0.00 0.00 0.00 W17 8.00 15.38 136.00 3.40 17.00 0.22 W17 9.00 17.3122.00 0.50 2.44 0.03 W17 15.00 28.85 1575.00 39.30 105.00 1.36 W17 10.0019.23 1037.00 25.90 103.70 1.35 W17 10.00 19.23 1236.00 30.90 123.601.61 W18 6.20 51.67 1786.60 56.99 288.16 1.10 W18 5.80 48.33 1348.3043.01 232.47 0.89 W19 3.97 42.69 1537.00 79.00 387.15 1.85 W19 1.2213.12 336.00 17.00 275.41 1.30 W19 4.11 44.19 73.60 4.00 17.91 0.09 W206.00 12.00 547.00 13.90 91.17 1.16 W20 17.00 34.00 1270.00 32.30 74.710.95 W20 21.00 42.00 1680.00 42.80 80.00 1.02 W20 6.00 12.00 430.0010.90 71.67 0.91 W21 7.00 21.21 1396.00 90.80 199.43 4.28 W21 6.00 18.180.00 0.00 0.00 0.00 W21 20.00 60.61 141.00 9.20 7.05 0.15 W22 5.25 18.68139.00 5.36 26.48 0.29 W22 3.75 13.34 211.00 8.14 56.27 0.61 W22 10.7638.28 628.00 24.23 58.36 0.63 W22 3.02 10.74 745.00 28.74 246.69 2.68W22 5.33 18.96 869.00 33.53 163.04 1.77 W23 7.00 12.87 540.00 20.2977.14 1.58 W23 18.00 33.09 111.16 4.11 6.18 0.12 W23 12.00 22.06 733.4727.56 61.12 1.25 W23 6.00 11.03 74.14 2.74 12.36 0.25 W23 8.40 15.44274.62 10.32 32.69 0.67 W23 3.00 5.51 929.02 34.98 309.67 6.34 W24 7.0012.73 502.00 17.35 71.71 1.36 W24 18.00 32.73 55.80 1.93 3.10 0.06 W2412.00 21.82 806.00 27.86 67.17 1.28 W24 6.00 10.91 254.00 8.78 42.330.80 W24 12.00 21.82 1275.00 44.07 106.25 2.02 W25 1.99 6.07 5.72 0.272.87 0.04 W25 1.83 5.58 79.40 3.72 43.39 0.67 W25 4.88 14.89 349.0016.35 71.52 1.10 W25 3.20 9.76 0.00 0.00 0.00 0.00 W25 1.98 6.04 253.0011.86 127.78 1.96 W25 8.99 27.43 249.00 11.67 27.70 0.43 W25 6.86 20.93743.00 34.82 108.31 1.66 W25 3.05 9.30 455.00 21.32 149.18 2.29

(2) Determination of the Yield Contribution Values Per Unit Thicknessfor Single-Reservoir Stratum

The single layer of which the yield contribution value per unitthickness for single-reservoir stratum is too low is not sufficient toinfluence the water-flooding development of the oil pool, and does nothave a value for thief zone recognition, thus, there is a need ofdetermining a smallest yield contribution value per unit thickness forsingle-reservoir stratum. Due to the differences in the factors such asthe physical properties of the oil pool, the smallest yield contributionvalues per unit thickness for single-reservoir stratum of different oilpools should be different, and generally can be a half of the averagevalue of the yield contribution values per unit thickness forsingle-reservoir stratum. The average value of the yield contributionvalues per unit thickness for single-reservoir stratum in thisembodiment is 98.53 stb/ft, and the smallest yield contribution valueper unit thickness for single-reservoir stratum can be 50 stb/ft.

(3) Determination of the Relative Contribution Coefficient for the ThiefZone Judging

The relative contribution coefficient is a ratio of the yieldcontribution value per unit thickness for single-reservoir stratum tothe total yield per unit thickness, the larger value for the ratio is,the greater the productivity of the single layer is. The contribution ofthe productivity of the thief zone is greater than that of the overallproductivity of the reservoir stratums. In general, the relativecontribution coefficient for thief zone judging is greater than or equalto 2, and is 2 in this example.

(4) Drawing a Discrimination Graph of the Relative ContributionCoefficient and the Yield Contribution Value Per Unit Thickness forSingle-Reservoir Stratum.

The discrimination graph is drawn by taking the yield contribution valueper unit thickness for single-reservoir stratum as the abscissa, and therelative contribution coefficient as the ordinate. According to thejudging conditions applicable for different oil pools, thediscrimination graph of the relative contribution rates and the per unityield contributions is divided into three areas. The smallest yieldcontribution value per unit thickness for single-reservoir stratum inthis embodiment is 50 stb/ft, the relative contribution coefficient forthief zone judging is 2, and the three discrimination areas (i.e., thearea that is not considered, the thief zone-developed area and the thiefzone-undeveloped area) are as shown in FIGS. 2 and 3.

(5) Performance of Thief Zone Recognition Based on the DiscriminationGraph

The recognition result is shown in FIG. 3, in which the area that is notconsidered, the thief zone-developed area and the thief zone-undevelopedarea are represented by means of dotted lines.

1. According to the discrimination graph of the relative contributionrates and the yield contribution values per unit thickness forsingle-reservoir stratum, in the data in this embodiment, data points(the data points include: yield contribution values per unit thicknessfor single-reservoir stratum and the relative contribution coefficients)of 72 single layers are located on the left of the graph (i.e., in thearea that is not considered), in other words, the abscissa valuesthereof are smaller than the smallest yield contribution value per unitthickness for single-reservoir stratum. It indicates that the per unityield contributions of this layer are not sufficient to cause influencesto the water-flooding development of the oil pool, and thus are notconsidered.

2. Data points of 21 single layers are located on the lower right sideof the discrimination graph (i.e., in the thief zone-undeveloped area).The per unit yield contributions of these single layers have reached thelevel that can influence the water-flooding development of the oil pool,but the relative contribution coefficients are relative low, and thusthese layers are recognized to be non-thief zones.

3. Data points of 17 single layers are distributed on the upper rightside of the discrimination graph (i.e., in the thief zone-developedarea). It indicates that the per unit yield contribution values thereofhave reached the level that can influence the water-flooding developmentof the oil pool, and the relative contribution coefficients are higherthan that of the ordinary reservoir stratums, and thus these layers arerecognized to be thief zones.

The embodiments of the present invention also provide a computerreadable storage medium comprising computer readable instructions, andthe computer readable instructions enable the processor to at leastexecute the following operations when the computer readable instructionsare executed: calculating a yield contribution value per unit thicknessfor single-reservoir stratum and a relative contribution coefficient ofindividual reservoir stratums in oil pool production logging, wherein,the yield contribution value per unit thickness for single-reservoirstratum is a ratio of a single-reservoir stratum yield to asingle-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval; determining a smallest yieldcontribution value per unit thickness for single-reservoir stratum and asmallest relative contribution coefficient from the yield contributionvalues per unit thickness for single-reservoir stratum and the relativecontribution coefficients in the oil pool production logging, accordingto the characteristics of different oil pools, wherein, the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient meet the requirementsof thief zone recognition for different oil pools; calculating the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient of each reservoir stratum of eachwell in the oil pool to-be-measured; determining whether or not a thiefzone is developed for each reservoir stratum of each well, according toa magnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.

In one embodiment, the above computer readable instructions enable theprocessor to: draw a graph by taking the yield contribution value perunit thickness for single-reservoir stratum of individual reservoirstratum in the oil pool production logging as an ordinate and therelative contribution coefficient of individual reservoir stratum in theoil pool production logging as an abscissa, wherein, an intersectionline of the smallest yield contribution value per unit thickness forsingle-reservoir stratum and the smallest relative contributioncoefficient divides the graph into different areas; and determinewhether or not a thief zone is developed for each reservoir stratum ofeach well according to the distribution positions of the yieldcontribution value per unit thickness for single-reservoir stratum ofeach reservoir stratum of each well and the relative contributioncoefficient of each reservoir stratum of each well in different areas ofthe graph.

In one embodiment, the above computer readable instruction enable theprocessor: not to judge the reservoir stratum of which the yieldcontribution value per unit thickness for single-reservoir stratum issmaller than the smallest yield contribution value per unit thicknessfor single-reservoir stratum; to determine the reservoir stratum ofwhich the yield contribution value per unit thickness forsingle-reservoir stratum is greater than the smallest yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient is smaller than the smallest relativecontribution coefficient to be a non-thief zone; and to determine thereservoir stratum of which the yield contribution value per unitthickness for single-reservoir stratum is greater than the smallestyield contribution value per unit thickness for single-reservoir stratumand the relative contribution coefficient is greater than the smallestrelative contribution coefficient to be a thief zone.

In a concrete implementation, the above computer readable storage mediumcan comprise a physical device for storage of information, which candigitize the information and store the information with an electrical, amagnetic, or an optical medium. The computer readable storage medium inthis embodiment can comprise: a device that uses electrical energy tostore information, which can be various types of memories such as a RAM,a ROM, etc.; a device that uses magnetic energy to store information,which can be a hard disc, a floppy disk, a magnetic tape, a magneticcore memory, a magnetic bubble memory, a usb flash disk, etc.; and adevice that stores information through optical means, which can be a CD,a DVD, etc. Of course, there are other types of readable storage media,such as a quantum memory, a graphene memory, etc.

The embodiments of the present invention also provide a computerapparatus, as shown in FIG. 4, the computer apparatus comprises: aprocessor 401; and a memory 402 comprising computer readableinstructions, the memory 402 coupled to the processor 401. The computerreadable instructions enable the processor to at least execute thefollowing operations when the computer readable instructions areexecuted: calculating a yield contribution value per unit thickness forsingle-reservoir stratum and a relative contribution coefficient ofindividual reservoir stratum in the oil pool production logging,wherein, the yield contribution value per unit thickness forsingle-reservoir stratum is a ratio of a single-reservoir stratum yieldto a single-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval; determining a smallest yieldcontribution value per unit thickness for single-reservoir stratum and asmallest relative contribution coefficient, from the yield contributionvalues per unit thickness for single-reservoir stratum and the relativecontribution coefficients in the oil pool production logging, accordingto the characteristics of different oil pools, wherein, the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient meet the requirementsof thief zone recognition for different oil pools; calculating the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient of each reservoir stratum of eachwell in the oil pool to-be-measured; determining whether or not a thiefzone is developed for each reservoir stratum of each well, according toa magnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.

In one embodiment, the above computer readable instructions enable theprocessor: to draw a graph by taking the yield contribution value perunit thickness for single-reservoir stratum of individual reservoirstratum in the oil pool production logging as an ordinate and therelative contribution coefficient of individual reservoir stratum in theoil pool production logging as an abscissa, wherein, an intersectionline of the smallest yield contribution value per unit thickness forsingle-reservoir stratum and the smallest relative contributioncoefficient divides the graph into different areas; and to determinewhether or not a thief zone is developed for each reservoir stratum ofeach well, according to the distribution positions of the yieldcontribution value per unit thickness for single-reservoir stratum ofeach reservoir stratum of each well and the relative contributioncoefficient of each reservoir stratum of each well in different areas ofthe graph.

In one embodiment, the above computer readable instructions enable theprocessor: not to judge the reservoir stratum of which the yieldcontribution value per unit thickness for single-reservoir stratum issmaller than the smallest yield contribution value per unit thicknessfor single-reservoir stratum; to determine the reservoir stratum ofwhich the yield contribution value per unit thickness forsingle-reservoir stratum is greater than the smallest yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient is smaller than the smallest relativecontribution coefficient to be a non-thief zone; and to determine thereservoir stratum of which the yield contribution value per unitthickness for single-reservoir stratum is greater than the smallestyield contribution value per unit thickness for single-reservoir stratumand the relative contribution coefficient is greater than the smallestrelative contribution coefficient to be a thief zone.

In the embodiments of the present invention, whether or not a thief zoneis developed for each reservoir stratum of each well can be determinedquickly by: calculating the yield contribution value per unit thicknessfor single-reservoir stratum and the relative contribution coefficientof individual reservoir stratums in the oil pool production logging (forexample, the yield contribution value per unit thickness forsingle-reservoir stratum and the relative contribution coefficient ofindividual reservoir stratum in the oil pool production logging can becalculated based on dynamic monitoring data on the oil pool productionlogging), determining the smallest yield contribution value per unitthickness for single-reservoir stratum and the smallest relativecontribution coefficient according to the characteristics of differentoil pools, and at last, whether or not a thief zone is developed foreach reservoir stratum of each well can be determined fast according toa magnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient. Sincethe calculation of the yield contribution value per unit thickness forsingle-reservoir stratum and the relative contribution coefficient hasfully considered the influence of thickness on yield contribution, thethief zone recognition is allowed to be more in line with actualsituations, thus helping improving the accuracy of the thief zonerecognition.

The persons skilled in the art shall understand that the embodiments ofthe present invention can be provided as a method, a system, or acomputer program product. Therefore, the present invention can beimplemented in the form of a complete hardware embodiment, a completesoftware embodiment, or an embodiment that combines software andhardware. In addition, the present invention can be implemented in theform of a computer program product which is implemented on a computerapplicable storage medium (including but not limited to a disk memory, aCD-ROM, an optical memory, etc.) that includes computer applicableprogram codes.

The present invention is described with reference to the flow chartand/or block diagram of the method, apparatus (system) and computerprogram product according to the embodiments of the present invention.It should be understood that each procedure and/or box in the flow chartand/or block diagram and a combination of the procedures and/or boxes inthe flow chart and/or block diagram can be realized by means of thecomputer program instructions. The computer program instructions can beprovided to a general-purpose computer, a special-purpose computer, anembedded processor or a processor of other programmable data processingapparatuses to produce a machine, so that the instructions executed bythe computer or the processor of other programmable data processingapparatuses generate a device used for realizing the functions specifiedin one or more procedures in the flow chart and/or one or more boxes inthe block diagram.

These computer program instructions can also be stored in a computerreadable memory that can guide the computer or other programmable dataprocessing apparatuses to work in a specific way, so that theinstructions stored in the computer readable memory generate amanufacture including an instruction device, which instruction devicerealizes the functions specified in one or more procedures in the flowchart and/or one or more boxes in the block diagram.

These computer program instruction can also be loaded on a computer orother programmable data processing apparatuses, so that a series ofoperation steps are executed on the computer or other programmableapparatuses to generate the processing realized by the computer, andthus, the instructions executed on the computer or other programmableapparatuses provide steps for realizing the functions specified in oneor more procedures in the flow chart and/or one or more boxes in theblock diagram.

The above mentioned specific embodiments further explain the object, thetechnical solutions and the advantageous effects of the presentinvention. It should be understood that the above content is merely thespecific embodiments of the present invention, and is not used to limitthe protection scope of the present invention. Any amendments,equivalent substitutions and improvements within the spirit andprinciple of the present invention should be included in the protectionscope of the present invention.

1. A method for recognizing a thief zone in an oil pool, comprising:calculating a yield contribution value per unit thickness forsingle-reservoir stratum and a relative contribution coefficient ofindividual reservoir stratum in oil pool production logging, wherein,the yield contribution value per unit thickness for single-reservoirstratum is a ratio of a single-reservoir stratum yield to asingle-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval; determining a smallest yieldcontribution value per unit thickness for single-reservoir stratum and asmallest relative contribution coefficient from the yield contributionvalues per unit thickness for single-reservoir stratum and the relativecontribution coefficients in the oil pool production logging, accordingto the characteristics of different oil pools, wherein, the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient meet the requirementsof thief zone recognition for different oil pools; calculating the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient of each reservoir stratum of eachwell in the oil pool to-be-measured; and determining whether or not athief zone is developed for each reservoir stratum of each well,according to a magnitude relationship between the yield contributionvalue per unit thickness for single-reservoir stratum of each reservoirstratum of each well and the smallest yield contribution value per unitthickness for single-reservoir stratum and according to a magnituderelationship between the relative contribution coefficient of eachreservoir stratum of each well and the smallest relative contributioncoefficient.
 2. The method for recognizing a thief zone in an oil poolaccording to claim 1, wherein determining whether or not a thief zone isdeveloped for each reservoir stratum of each well according to amagnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficientcomprises: drawing a graph by taking the yield contribution value perunit thickness for single-reservoir stratum of individual reservoirstratum in the oil pool production logging as an ordinate and therelative contribution coefficient of individual reservoir stratum in theoil pool production logging as an abscissa, wherein, an intersectionline of the smallest yield contribution value per unit thickness forsingle-reservoir stratum and the smallest relative contributioncoefficient divides the graph into different areas; and determiningwhether or not a thief zone is developed for each reservoir stratum ofeach well, according to distribution positions of the yield contributionvalue per unit thickness for single-reservoir stratum of each reservoirstratum of each well and the relative contribution coefficient of eachreservoir stratum of each well in the different areas of the graph. 3.The method for recognizing a thief zone in an oil pool according toclaim 1, wherein determining whether or not a thief zone is developedfor each reservoir stratum of each well according to a magnituderelationship between the yield contribution value per unit thickness forsingle-reservoir stratum of each reservoir stratum of each well and thesmallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficientcomprises: not judging the reservoir stratum of which the yieldcontribution value per unit thickness for single-reservoir stratum issmaller than the smallest yield contribution value per unit thicknessfor single-reservoir stratum; determining the reservoir stratum of whichthe yield contribution value per unit thickness for single-reservoirstratum is greater than the smallest yield contribution value per unitthickness for single-reservoir stratum and the relative contributioncoefficient is smaller than the smallest relative contributioncoefficient to be a non-thief zone; and determining the reservoirstratum of which the yield contribution value per unit thickness forsingle-reservoir stratum is greater than the smallest yield contributionvalue per unit thickness for single-reservoir stratum and the relativecontribution coefficient is greater than the smallest relativecontribution coefficient to be a thief zone.
 4. The method forrecognizing a thief zone in an oil pool according to claim 1, whereinfor a carbonatite oil pool, the smallest yield contribution value perunit thickness for single-reservoir stratum is 50, and the smallestrelative contribution coefficient is
 2. 5. A computer apparatuscomprising a processor and a memory comprising computer readableinstructions, the processor being enabled to execute the followingoperations when the computer readable instructions are executed:calculating a yield contribution value per unit thickness forsingle-reservoir stratum and a relative contribution coefficient ofindividual reservoir stratum in oil pool production logging, wherein,the yield contribution value per unit thickness for single-reservoirstratum is a ratio of a single-reservoir stratum yield to asingle-reservoir stratum thickness, and the relative contributioncoefficient is a ratio of the yield contribution value per unitthickness for single-reservoir stratum to a yield per unit thickness forthe whole reservoir stratum interval; determining a smallest yieldcontribution value per unit thickness for single-reservoir stratum and asmallest relative contribution coefficient, from the yield contributionvalues per unit thickness for single-reservoir stratum and the relativecontribution coefficients in the oil pool production logging, accordingto the characteristics of different oil pools, wherein, the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient meet the requirementsof thief zone recognition for different oil pools; calculating the yieldcontribution value per unit thickness for single-reservoir stratum andthe relative contribution coefficient of each reservoir stratum of eachwell in the oil pool to-be-measured; and determining whether or not athief zone is developed for each reservoir stratum of each well,according to a magnitude relationship between the yield contributionvalue per unit thickness for single-reservoir stratum of each reservoirstratum of each well and the smallest yield contribution value per unitthickness for single-reservoir stratum and according to a magnituderelationship between the relative contribution coefficient of eachreservoir stratum of each well and the smallest relative contributioncoefficient.
 6. The computer apparatus according to claim 5, wherein thecomputer readable instructions enable the processor to: draw a graph bytaking the yield contribution value per unit thickness forsingle-reservoir stratum of individual reservoir stratum in the oil poolproduction logging as an ordinate and the relative contributioncoefficient of individual reservoir stratum in the oil pool productionlogging as an abscissa, wherein, an intersection line of the smallestyield contribution value per unit thickness for single-reservoir stratumand the smallest relative contribution coefficient divides the graphinto different areas; and determine whether or not a thief zone isdeveloped for each reservoir stratum of each well, according to thedistribution positions of the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the relative contribution coefficient of each reservoir stratumof each well in the different areas of the graph.
 7. The computerapparatus according to claim 5, wherein the computer readableinstructions enable the processor: not to judge the reservoir stratum ofwhich the yield contribution value per unit thickness forsingle-reservoir stratum is smaller than the smallest yield contributionvalue per unit thickness for single-reservoir stratum; to determine thereservoir stratum of which the yield contribution value per unitthickness for single-reservoir stratum is greater than the smallestyield contribution value per unit thickness for single-reservoir stratumand the relative contribution coefficient is smaller than the smallestrelative contribution coefficient to be a non-thief zone; and todetermine the reservoir stratum of which the yield contribution valueper unit thickness for single-reservoir stratum is greater than thesmallest yield contribution value per unit thickness forsingle-reservoir stratum and the relative contribution coefficient isgreater than the smallest relative contribution coefficient to be athief zone.
 8. A computer readable storage medium comprising computerreadable instructions, wherein the computer readable instructions enablea processor to at least execute the following operations when thecomputer readable instructions are executed: calculating a yieldcontribution value per unit thickness for single-reservoir stratum and arelative contribution coefficient of individual reservoir stratum in oilpool production logging, wherein, the yield contribution value per unitthickness for single-reservoir stratum is a ratio of a single-reservoirstratum yield to a single-reservoir stratum thickness, and relativecontribution coefficient is a ratio of the yield contribution value perunit thickness for single-reservoir stratum to a yield per unitthickness for the whole reservoir stratum interval; determining asmallest yield contribution value per unit thickness forsingle-reservoir stratum and a smallest relative contributioncoefficient, from the yield contribution values per unit thickness forsingle-reservoir stratum and the relative contribution coefficients inthe oil pool production logging, according to the characteristics ofdifferent oil pools, wherein, the smallest yield contribution value perunit thickness for single-reservoir stratum and the smallest relativecontribution coefficient meet the requirements of thief zone recognitionfor different oil pools; calculating the yield contribution value perunit thickness for single-reservoir stratum and the relativecontribution coefficient of each reservoir stratum of each well in theoil pool to be measured; and determining whether or not a thief zone isdeveloped for each reservoir stratum of each well, according to amagnitude relationship between the yield contribution value per unitthickness for single-reservoir stratum of each reservoir stratum of eachwell and the smallest yield contribution value per unit thickness forsingle-reservoir stratum and according to a magnitude relationshipbetween the relative contribution coefficient of each reservoir stratumof each well and the smallest relative contribution coefficient.
 9. Thecomputer readable storage medium comprising computer readableinstructions according to claim 8, wherein the computer readableinstructions enable the processor to: draw a graph by taking the yieldcontribution value per unit thickness for single-reservoir stratum ofindividual reservoir stratum in the oil pool production logging as anordinate and the relative contribution coefficient of individualreservoir stratum in the oil pool production logging as an abscissa,wherein, an intersection line of the smallest yield contribution valueper unit thickness for single-reservoir stratum and the smallestrelative contribution coefficient divides the graph into differentareas; and determine whether or not a thief zone is developed for eachreservoir stratum of each well, according to the distribution positionsof the yield contribution value per unit thickness for single-reservoirstratum of each reservoir stratum of each well and the relativecontribution coefficient of each reservoir stratum of each well in thedifferent areas of the graph.
 10. The computer readable storage mediumcomprising computer readable instructions according to claim 8, whereinthe computer readable instructions enable the processor: not to judgethe reservoir stratum of which the yield contribution value per unitthickness for single-reservoir stratum is smaller than the smallestyield contribution value per unit thickness for single-reservoirstratum; to determine the reservoir stratum of which the yieldcontribution value per unit thickness for single-reservoir stratum isgreater than the smallest yield contribution value per unit thicknessfor single-reservoir stratum and the relative contribution coefficientis smaller than the smallest relative contribution coefficient to be anon-thief zone; and to determine the reservoir stratum of which theyield contribution value per unit thickness for single-reservoir stratumis greater than the smallest yield contribution value per unit thicknessfor single-reservoir stratum and the relative contribution coefficientis greater than the smallest relative contribution coefficient to be athief zone.